Medical electrodes are needed in many applications, e.g. for measurement of electrical activity in the brain (EEG), the heart (ECG), or the muscles (EMG). Medical electrodes may be used for measuring, e.g., electric current, potential/voltage, skin conductance, and skin resistance. Certain medical electrodes may also be used for supplying electrical energy into the patient, e.g. in the case of defibrillators, electroconvulsive therapy and other therapy methods.
Medical electrodes are also used in the fields of electrophysiology and neuroscience. A particular class of equipment and methods utilize measurement of skin conductance for assessing the state of the autonomous nervous system of a patient, such as a sedated patient, e.g. for detecting pain or awakening during anaesthesia.
WO-03/094726 is an example of an apparatus and a method for monitoring the autonomous nervous system of a sedated patient, wherein the skin conductance, measured by use of electrodes placed on the skin of the patient, is measured. Signals indicating pain/discomfort in the patient and awakening in the patient are derived from the skin conductance measurements.
Medical electrode patches are often fixed to the skin by means of an adhesive. It is well known that the use of adhesive directly on the skin may result in an irritation of the patient's skin. This is particularly significant in the case of neonatal or preterm infants, since their skin is very vulnerable for adhesives.
When neonates are placed in an incubator, the humidity is particularly high. In such humid environments there is particularly difficult to make adhesive electrodes stick to the neonate's skin.